The present invention relates to a new and improved winding device for automatically changing bobbin tubes and constitutes an improvement upon the commonly assigned, copending U.S. application Ser. No. 447,853, filed Mar. 4, 1974, now U.S. Pat. No. 3,920,193 granted Nov. 18, 1975 and entitled "Winding Apparatus With Automatic Changing Of Tubes Or The Like", listing as the inventors Peter Gujer, Hans Schellenberg and Olivier Wuest.
In the aforementioned copending application there is taught to the art a winding device for automatically changing tubes for taking-up endless threads, filaments or the like --hereinafter generically simply broadly referred to as threads-- , the winding device being of the type provided with a thread traversing device for generating threading winding-wraps, a thread deflecting device for lifting the thread-off the thread traversing device. There is further provided a thread holding device with a thread guiding device for guiding the thread in its lifted-off position during the change of the bobbin tube, and at least two driven bobbin chucks alternately brought into a bobbin or tube change position respectively, each of the bobbin chucks supporting one tube. A thread catching- and cutting zone is arranged adjacent to one end of the associated tube and rotates with such tube. The thread holding device is arranged such that the thread lifted-off the thread traversing device is guided thereby in the immediate vicinity of the thread catching- and cutting zone. A thread shifting means is provided for shifting the thread guided by the thread holding device in a first shifting step or phase from a position at the immediate vicinity of the threading catching and cutting zone through such zone and onto an end portion of the tube adjacent thereto, the thread shifting means in a second step or phase shifting the thread over a predetermined distance on the tube for creating reserve wraps, with the thread shifting means shifting the thread at a higher shifting speed during the second step or phase than during the first step or phase. During operation of this system there is produced a reserve winding --also called fixation winding-- before the second shifting step is carried out, such reserve winding comprising a number of closely adjacent windings or wraps which are produced in such a manner that there can be obtained a sufficiently long, however, if possible, not a dangling thread reserve.